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Liquid targets for isotope production
Jerry Nolen
Physics Division, Argonne National Laboratory
NuFact'11 XIIIth Workshop on Neutrino Factories, Superbeams and Beta-beams
CERN and University of Geneva
August 3, 2011
This work was supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357.
2Nufact11, Beta Beam Physics, Elena Wildner2011-08-02 2Nufact11, Beta Beam Physics, Elena Wildner 2
High-Q and Low-Q pairsIsotope 6He 18Ne
A/Z 3 1.8
decay - +
1/2 [s] 0.81 1.67
Q [MeV] 3.51 3.0
Isotope 8Li 8B
A/Z 2.7 1.6
decay - +
1/2 [s] 0.83 0.77
Q [MeV] 12.96 13.92NuBase
t1/2 at rest (ground state)
1 – 60 s1ms – 1s
6He and 18Ne
8Li and 8B
Higher Q-value gives higher -energy, better x-sections but needs longer baseline
3Nufact11, Beta Beam Physics, Elena Wildner2011-08-02 3Nufact11, Beta Beam Physics, Elena Wildner 3
CERN Beta Beams, Synoptic
SPS
PS DR
RCSSPL Linac4
ISOL target
Molten Salt Loop
6He 18Ne -Beam
RFQ
ECR
Linac
Collection
6He/18Ne
8B/8Li
Linac 100 MeV
Dotted lines: alternative layoutsDotted lines: alternative layouts
RCS
Decay Ring: B ~ 500 Tm, B = ~6 T, C = ~6900 m, Lss= ~2500 m, = 100, all ionsDecay Ring: B ~ 500 Tm, B = ~6 T, C = ~6900 m, Lss= ~2500 m, = 100, all ions
PS and SPS existingPS and SPS existing
Baseline
PR
4Nufact11, Beta Beam Physics, Elena Wildner2011-08-02 4Nufact11, Beta Beam Physics, Elena Wildner
The Production Ring (8B and 8Li)
4
High-Q 8B and 8Li will not be considered for the time being
We will not explore the low-Q gamma 350 option
Gas Jet target proposed in FP7: too high density would be needed vacuum problems
Direct Production (D. Neuffer) with liquid film targets Collaboration ANL (Benedetto/Nolen)
Production of 8B and 8LiC. Rubbia, EUROnu proposal
Aachen Univ., GSI, CERN
Can liquid lithium targets be used at the necessary power levels?
“Inverse”: 6Li beam on 3He gas jet. “Direct”: 3He beam on 6Li target.
E. Benedetto, ICE Meeting, 25/1/11
Direct vs. inverse kinematics
8Li/8B emitted at10o
similar energy as projectile
Supersonic jet target
Efficient cooling removal
Low densities
Collection + diff./effusion
30o emission angle and smaller velocity
Larger M.C. Scattering
Larger emittance, less SC
Solid/liquid target
Cooling / jet instabilities
High densities
Collection? Spectrometer?
INVERSE DIRECT
See also D. Neuffer, NIM A 585 (2008) 109
Liquid targets for isotope production6
Production/cooler rings: direct or inverse kinematics
Liquid targets for isotope production7
Recent presentation by the Argonne liquid lithium group
Thin liquid lithium targets for high power density applications: heavy ion
beam strippers and beta beam production
Claude Reed, Jerry Nolen, Yoichi Momozaki, Jim Specht, Dave Chojnowski, Ron Lanham, Boni Size, and Richard McDaniel
Nuclear Engineering Division and Physics Division
Presented at4th High Power Targetry Workshop
May 2nd to May 6th 2011Hilton Malmö City
Liquid targets for isotope production8
Thick target and thin target development
JInst 4:P04005 (2009)
20 kW beam on Target
9High Power Targets for Radioactive Beam Facilities
High Power Test of a Liquid-Lithium Fragmentation Target
A 20 kW electron beam produces the same thermal load as a 200 kW U beam on the windowless liquid Li target.
20 kW beam on Target
beam spot
nozzle
Li jet
Flo
w @
8
m/s
Side view
5 mm
10 mm
beamto viewport
nozzle
20o
Top view
Li jet is confirmed stable in vacuum with a U beam equivalent thermal load.
Power density is 8 MW/cm3 @ 400 kW beam power at 200 MeV/u.
Thermal Design Analysis for Liquid Metal Windowless Targets
Y. Momozaki, J. A. Nolen, C. B. Reed, J. Bailey, and P. Strons
The Third High-Power Targetry Workshop
by Paul Scherrer Institut
September 10 to 14, 2007
Bad Zurzach, Switzerland
11
20 kW E-beam-on-Target Test at ANL
MCNPX :
for RIA, 200-kW uranium beam on Li peak energy deposition = 2 MW/cm3
1MeV, 20 mA, 1mm e-beam on Li deposited in the first 4 mm
Test Objectives:
Using this equivalence, demonstrate that power densities equivalent to a 200 kW RIA uranium beam:
• Do not disrupt the Li jet flow• Li T (across beam spot) is modest (~ 180º C)• Li vapor pressure remains low
Overall Objective:
To show that 2 MW/cm3, deposited in the first 4 mm of the flowing lithium jet, can be handled by the windowless target
}Background
12
What Experiment Indicates: power density for 1-MeV, 20-kW e-beam
Thermal analysis– 3D Results (using Star CD)
10 mm
2.5 mm
e-beam
Estimated maximum temperature in the Li target is 872 K.
13
Thermal Design Analysis for a liquid tin beam dump for uranium beams
Estimated maximum temperature in the Li target is 912 K (Psat ~ 1.810-7 Pa for Sn).
Sn beam-dump for AEBL, ANL, USA
118
3552
6986
S1
S10
500
550
600
650
700
750
800
850
900
950 900-950
850-900
800-850
750-800
700-750
650-700
600-650
550-600
500-550
Beam
center at
0.02 m,
= 0.015 m
Liquid targets for isotope production14
Power density expectations give limitations for internal thin liquid lithium target size and speed Our prediction is for a peak temperature of 941K in a 13 micron thick film flowing
at 58 m/s and 624 W deposited by a uranium beam with a 3σ beam width of 1 mm– Because of the high speed linear flow only the beam width is relevant– A 13 micron film is 0.65 mg/cm2, so a 1 mg/cm2 thickness can take 960 W/(mg/cm2)
per mm of width– From David Neuffer’s paper the internal target can be 3.6 mg/cm2 in thickness, and
hence can take 3.5 kW per mm of width– He also predicts a power deposit from the 3He beam of 500 kW, so the width of the
beam spot must be 143 mm at 58 m/s to keep the same temperature rise– If we can increase the speed to 200 m/s then the width can be 41 mm
Issues:– The beam spot can be 41mm wide by 1mm tall, so is this size beam on target
compatible with the ring optics? (the slit-shaped beam is probably good for the recoil collection geometry)
– Can we scale the speed to 200 m/s or more? (requires ~500 psia pressure – probably OK)
– Can we make a film 41 mm wide and 72 microns thick? (I think so)
Liquid targets for isotope production15
Other potential uses of liquid metal technology at neutrino factories
Alternative for production of 8B via fragmentation of 10B– ~1 MW 10B beam at ~200 MeV/u can produce in-flight 1E13 8B per
second using a liquid lithium cooled target– The 8B is formed at high energy and already fully stripped– Studies of transverse and longitudinal cooling are necessary to
compare overall rates with “ISOL” methods The 2-step 6He production target can probably benefit from
liquid lithium cooling of the tungsten neutron converter The “pebble-bed” pion production target concept can
probably benefit from liquid lithium cooling of the pebbles
Liquid targets for isotope production16
Concept for a liquid-lithium cooled tungsten neutron converter for radioactive beams of fission fragmentsThis concept is applied to production of 6He by replacing the uranium with BeO
Liquid lithium cooling enables a more compact geometry
Packed Bed Target Concept for Euronu
(or other high power beams)
Packed bed cannister in parallel flow configuration
Packed bed target front end
Model ParametersProton Beam Energy = 4.5GeVBeam sigma = 4mmPacked Bed radius = 12mmPacked Bed Length = 780mmPacked Bed sphere diameter = 3mmPacked Bed sphere material : Beryllium or TitaniumCoolant = Helium at 10 bar pressure
Titanium alloy cannister containing packed bed of titanium or beryllium spheres
Cannister perforated with elipitical holes graded in size along length
Slide from Tristan Davenne at EUROnu’11:Liquid metal cooling can be considered
Liquid targets for isotope production18
Summary Initial estimates indicate that 8B production via 3He
stored beam on a thin 6Li target is not far from feasible (2H beam on 7Li target is less demanding)
Beam-on-target tests of the thin lithium film is the next priority for the FRIB stripper development
An update of the ring parameters required for necessary production rates should be done
Ring and cooling/heating dynamics with a slit-shaped beam spot on target must be investigated
Liquid lithium technology is possibly applicable in other aspects of neutrino factory targetry